Billaea micronychia Zhang et Shima

Zhang, Chun-Tian, Shima, Hiroshi, Wang, Qiang & Tschorsnig, Hans-Peter, 2015, A review of Billaea Robineau-Desvoidy of the eastern Palearctic and Oriental regions (Diptera: Tachinidae), Zootaxa 3949 (1), pp. 1-40 : 17-19

Billaea micronychia Zhang et Shima sp. nov.

Figs. 36–39, 82, 91

Billaea irrorata (Meigen) of Zhang et al. 2010: 1226 (misidentification).

Diagnosis. Body small to medium, arista short-haired, thorax with 5 black longitudinal vittae on scutum, 3 katepisternal setae, basicosta yellow, fore claws short in male, fore tibia with 2 posterior setae, abdominal tergite 3 with 2 median marginal setae.

Description. Body length 5.5–10.1 mm.

Male. Head ( Figs. 82 , 91 ). Black in ground color, gena reddish brown, frontal vitta and lunule dark brown; upper fronto-orbital plate with grayish pruinosity; parafacial and gena with grayish white pruinosity. Antenna black, base of flagellomere 1 and apex of pedicel narrowly reddish; palpus reddish yellow at apex and dark on basal 3/4. Vertex 0.20–0.23 of head width; frontal vitta strongly widened anteriorly, as wide as fronto-orbital plate at middle; parafacial bare, 2.0–2.3 times as wide as flagellomere 1; facial carina undeveloped; lower margin of face slightly protruding forward; genal height 0.34–0.45 of eye height in profile; occiput bulged on lower half. Frontoorbital plate with 2–4 rows of fine short hairs; inner vertical setae strong, about 3/5 as long as eye height; ocellar setae 0.7–1 times as long as inner vertical setae; post vertical setae 0.5–0.7 times as long as inner vertical setae; 10– 11 pairs of inclinate frontal setae. Flagellomere 1 about twice as long as wide and as pedicel; pedicel with a long seta which is slightly shorter than antenna; arista slightly longer than antenna, short-haired, total width including plumosity 0.5–0.6 times as wide as flagellomere 1. Prementum about 4 times as long as wide.

Thorax. Brownish black in ground color, with grayish white pruinosity; 5 black longitudinal vittae on scutum, outer vitta broad, about 1/2 as wide as pruinose portion between inner and outer vittae on presutural scutum, inner vittae extending to anterior 1/3 of postsutural scutum, median vitta extending to anterior margin of scutellum; scutellum black, with grayish yellow pruinosity; pleura brownish black, with grayish white pruinosity. Postpronotal lobe with 4–6 setae, 3 basal setae arranged in a triangle; 2–3 presutural and 2–4 postsutural acrostichal setae; 3 presutural and 4 postsutural dorsocentral setae; 3 postsutural intra-alar setae; 3 supra-alar setae, anteriormost seta weak, about 2/3 as long as notopleural seta; 3 katepisternal setae; scutellum with 4–6 discal setae, apical scutellar setae crossed, about 1.4 times as long as scutellum; subapical scutellar seta longer than apical seta. Wing. Hyaline, tinged with pale brown throughout; tegula brownish black; basicosta yellow; lower calypter pale yellowish white; halter dark brown and brownish at apex. Relative lengths of 2nd, 3rd and 4th costal sectors approximately as 4:8.3:5; bend of vein M almost right-angled, usually without appendix; vein M from dm-cu crossvein to its bend about 1.3 times distance between the bend and wing margin. Legs. Femora black, tibiae reddish brown to dark brown; claws black, pulvilli yellow. Fore claws and pulvilli shorter than 5th tarsomere; fore tibia with a row of anterodorsal setae and 2 posterior setae; mid tibia with 2 anterodorsal, 2–3 posterodorsal and 2 ventral (upper one fine and indistinct) setae; hind tibia with a row of short anterodorsal setae in equal length, 2–4 posterodorsal and 2 (upper one fine and indistinct) ventral setae.

Abdomen. Long ovate, brownish black, with gray white pruinosity on whole tergites; tergites 3 and 4 each with an indistinct trapezoidal brown marking on posterior 4/5. Recumbent black hairs on dorsum of tergites 3 and 4 in irregular 4–7 rows; syntergite 1+2 with 1 lateral marginal seta, without median marginal seta; tergite 3 with 2 strong median marginal and 1 lateral marginal setae. Male terminalia (Figs. 36–39). Median cleft of sternite 5 narrow, 0.6–0.8 of the sternite. Cerci narrowed at apical half; surstylus weakly pointed apically; postgonite about as long as basiphallus; distiphallus long, sclerotized basal part subequal in length to membranous apical part.

Female. Vertex 0.3–0.33 of head width, frontal vitta less than frontal orbital plate in width, gena 0.4–0.46 of eye height; 7–10 pairs of inclinate frontal setae, 2 strong proclinate orbital setae, 1 reclinate prevertical seta, outer vertical seta about 1/2 as long as inner vertical seta; mid tibia with 2–3 anterodorsal, 3 posterodorsal and 1 ventral setae; hind tibia with 2 strong anterodorsal setae among regularly set row of anterodorsal setae; abdomen ovate, shining black, with gray pruinosity on dorsum. Other characters are same as in male.

Type material. Holotype ♂, CHINA, Liaoning: Baishilazi (124°41′E, 41°07′N), 500–540 m, Kuandian, 19.viii.2007, C.-T. Zhang ( SYNU). Paratypes. CHINA. Hebei: 6♂♂, 5♀♀, Jinhekou, 1170 m, Xiaowutai Mountain, 18–24.v.2010, T. Li; 1♂, Mt. West Lingshan, 1400 m, Xiaowutai Mountain, Zhuolu, 26.vi.2009, Y.-Y. Zhou (misidentified as B. irrorata (Meigen) in Zhang et al. 2010: 1226). Jilin: 1♀, Songjianghe to Changbai, 1000–1965 m, 28–30.vii.2008, Z.-Y. Yao. Qinghai: 14♂♂, Huangyuan, emerged from pupae in 7–26.xi.2011, M.- L. Sheng & T. Li. 62♂♂, 14♀♀, body small, Dulan, emerged from pupae in 24.x–29.xi.2011, M.-L. Sheng & T. Li. Shanxi: Medium, abdomen with dense hairs. 1♂, Yanggetai, Fangshan, 24.vi.1990, M.-F. Wang; 1♂, Matian, Zuoquan, 12.vi.1999, M.-F. Wang; 1♂, Shanzhuangtou, Xiyang, 19.vi.1999, M.-F. Wang; 1♂, Xiachuan, Qinshui, 19.vi.1991, M.-F. Wang ( SYNU). JAPAN. Hokkaidō: 1♂, Tokachimimata, 27.iv.1987. Honshu: 1♂, Manza Spa, Gumma, 6.viii.1995, K. Hara; 1♂, Mt. Hachimori, Ashahi vill., Nagano Pref., 25.vii.1998, T. Tachi.

Etymology. The specific name is taken from a diagnostic character of this species; it is composed from the Greek adjective micro (small) plus the noun onychos (claw).

Host. This species is recorded from larvae of Saperda balsamifera Motschulsky ( Coleoptera , Cerambycidae ) in Qinghai, China. Host larvae dwell in branches of Populus tomentosa Carr and P. canadensis Moench. All the specimens from Qinghai emerged from host pupae at room temperature in the laboratory in Shenyang.

Distribution. China (Liaoning, Hebei, Jilin, Qinghai, Shanxi), Japan (Honshu).

Remarks. This new species is one of three species with short-haired arista, 5 dark longitudinal vittae on presutural scutum, 3 katepisternal setae, fore claws and pulvilli of male short and fore tibia with 2 posterior setae, and abdomen dark brown, the other species being B. irrorata ( Meigen, 1826) (not treated here) and B. fortis . Within this group of three species, B. micronychia and B. fortis are the only two without median marginal seta on abdominal syntergite 1+2, but B. micronychia differs from the latter in having smaller body, lower margin of face slightly protruding forward, prementum shorter, yellow basicosta, and tergite 3 with 2 strong median marginal setae and recumbent hairs sparse.

This species was misidentified as B. irrorata by Zhang et al. (2010) and was the first record of that species from China. Billaea irrorata is no longer recorded from the eastern Palearctic.

Figures

FIGURES 82 – 88. Billaea spp., heads of male in lateral view. 89 – 90. Abdomens in dorsal view. 82. B. micronychia sp. nov. 83. B. morosa Mesnil. 84. B. papei sp. nov. 85. B. setigera sp. nov. 86. B. steini (Brauer et Bergenstamm). 87. B. triangulifera (Zetterstedt). 88. B. verticalis sp. nov. 89. B. atkinsoni sp. nov. 90. B. chinensis sp. nov. Scale bars = 0.5 mm.

FIGURES 91 – 97. Billaea spp., heads of male in anterior view. 98 – 99. Abdomens in dorsal view. 91. B. micronychia sp. nov. 92. B. morosa Mesnil. 93. B. papei sp. nov. 94, 98. B. setigera sp. nov. 95. B. steini (Brauer et Bergenstamm). 96, 99. B. triangulifera (Zetterstedt). 97. B. verticalis sp. nov. Scale bars = 0.5 mm.